Date: Thu, 15 Feb 2018 10:56:45 +0100 From: Michael Schuster <michaelsprivate@gmail.com> To: Per olof Ljungmark <peo@nethead.se> Cc: FreeBSD Mailing List <freebsd-questions@freebsd.org> Subject: Re: which limit is hit here? Message-ID: <CADqw_gKJH5OPeXCin_344=yVRBeYXGP62NAZuTi9MMt6LDQzgA@mail.gmail.com> In-Reply-To: <0d45799f-cd71-86e2-9c70-d8da3b64364d@nethead.se> References: <d4d1093d-0db2-baed-0fb5-04b5127c8ccb@nethead.se> <CADqw_gKS=%2Be=PCgG6OJVfbuSwWD4zioZ__gnVNc5hYtM2Mfo%2Bg@mail.gmail.com> <71635f3b-0494-1956-fa31-bd8df7b72a93@nethead.se> <CADqw_g%2BQ0=jbqD9wnYnprXtrUvcz5Lg8AHGMmNrHO8K-UthOgQ@mail.gmail.com> <e29cfb8e-c199-4b5c-7580-71646c807a52@nethead.se> <CADqw_gKOr9va7-ffzVJYm4=kL=8m1PLGkqhY7AOQdpdgDNo_Tw@mail.gmail.com> <0d45799f-cd71-86e2-9c70-d8da3b64364d@nethead.se>
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On Thu, Feb 15, 2018 at 10:54 AM, Per olof Ljungmark <peo@nethead.se> wrote: > On 02/15/18 10:31, Michael Schuster wrote: > > > > > > On Thu, Feb 15, 2018 at 10:27 AM, Per olof Ljungmark <peo@nethead.se > > <mailto:peo@nethead.se>> wrote: > > > > > > > > On 02/15/18 10:07, Michael Schuster wrote: > > > hmm ... > > > > > > what does gdb's "info shared" print out? > > > > "No shared libraries loaded at this time." > > > > > > is that really all? > > Yes, that is what is says. > in that case, someone with more intimate knowledge of (and access to) FreeBSD and/or Cyrus-IMAP will have to step in ... sorry :-) Michael > > I'd expect something like this (library names removed by me) - this is > > not on BSD, btw, but I'd expect gdb to behave in a similar fashion: > > > > (gdb) info shared > > From To Syms Read Shared Object Library > > 0x01120000 0x011b090c Yes xxxx > > 0x78a3e000 0x78a64660 Yes (*) xxxxxx > > 0x78317000 0x7831d290 Yes (*) xxxxxx.so > > 0x78087000 0x78087000 No xxxxxxxxxxxx.so.1.1 > > 0x78056000 0x78056000 No xxxxxxxxxx.1.2 > > 0x7801f000 0x7801f000 No xxxxxxxxxxxxso.1.0 > > 0x7800c000 0x7800c000 No xxxxxxxxxx.so.1.0 > > 0x78000000 0x78000000 No xxxxxxxxxxxxxx.so.1.0 > > 0x78017000 0x78017000 No xxxxxxxxx.so.1.0 > > 0x78129000 0x7819f960 Yes xxxxxxso > > 0x78037000 0x78040768 Yes xxxxxxxx.so > > 0x78025000 0x7802f6e0 Yes xxxxxxxxso.2 > > 0x78047000 0x78054970 Yes xxxxxxxxxxx.so > > (*): Shared library is missing debugging information. > > (gdb) > > > > > > > > > > > > > > On Thu, Feb 15, 2018 at 10:06 AM, Per olof Ljungmark < > peo@nethead.se <mailto:peo@nethead.se> > > > <mailto:peo@nethead.se <mailto:peo@nethead.se>>> wrote: > > > > > > On 02/15/18 08:56, Michael Schuster wrote: > > > > Hi Per, > > > > > > > > On Thu, Feb 15, 2018 at 8:41 AM, Per olof Ljungmark < > peo@nethead.se <mailto:peo@nethead.se> <mailto:peo@nethead.se > > <mailto:peo@nethead.se>> > > > > <mailto:peo@nethead.se <mailto:peo@nethead.se> > > <mailto:peo@nethead.se <mailto:peo@nethead.se>>>> wrote: > > > > > > > > Hi, > > > > > > > > A process "squatter" from Cyrus-IMAP version 2.5.11 > > exits with signal > > > > 11. The purpose of the process is to create an index of > > the content in a > > > > mailbox. > > > > > > > > On large mailboxes, squatter coredumps, the final > > message from truss > > > > reads: > > > > > > > > > > mmap(0x0,700448768,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANON,-1,0x0) > = > > > > 34783363072 (0x819400000) > > > > mmap(0x0,936334732,PROT_READ,MAP_SHARED,107,0x0) = > > 35483811840 > > > > (0x843000000) > > > > SIGNAL 11 (SIGSEGV) > > > > process killed, signal = 11 (core dumped) > > > > > > > > > > > > to me this looks like the error is happening *after* mmap() > > returned > > > > successfully - most likely because "someone" miscalculates > > some pointer > > > > and tries to access an unmapped address. Maybe (but that's > > conjecture), > > > > PROT_READ is wrong here and someone is attempting to write > > to that > > > > mapped region; I'm not 100% sure though whether that'd > > actually trigger > > > > SIGSEGV. > > > > > > > > I'd suggest you do something like > > > > $ gdb squatter core > > > > (gdb) bt > > > > > > > > and look at the output, and maybe go to the maintainers of > > Cyrus-IMAP... > > > > > > Hi, > > > > > > gdb says, > > > > > > (gdb) bt > > > #0 0x00000000004049cc in ?? () > > > #1 0x0000000803456da4 in ?? () > > > #2 0x0000000804445130 in ?? () > > > #3 0x003875e5ffffcb00 in ?? () > > > #4 0x00000008047e7008 in ?? () > > > #5 0x00000008047e7048 in ?? () > > > #6 0x00000001040000c0 in ?? () > > > #7 0x0000000810800000 in ?? () > > > #8 0x0000000200000045 in ?? () > > > #9 0x000000083a400000 in ?? () > > > #10 0x00000008047e8e98 in ?? () > > > #11 0x00000000000003bb in ?? () > > > #12 0x00000008047e8eb8 in ?? () > > > #13 0x00000000000000bf in ?? () > > > #14 0x0ffd2a151071e550 in ?? () > > > #15 0x000000bf00000002 in ?? () > > > #16 0x37cf558c1298d1e7 in ?? () > > > #17 0x0135682800000000 in ?? () > > > #18 0x02e00a0e020d0336 in ?? () > > > #19 0x0487888c03b90d10 in ?? () > > > #20 0x062618da0556e126 in ?? () > > > #21 0x0000000006f31067 in ?? () > > > #22 0x0000000000000000 in ?? () > > > > > > > > > > > > > > > -- > > > Michael Schuster > > > http://recursiveramblings.wordpress.com/ > > <http://recursiveramblings.wordpress.com/>; > > > recursion, n: see 'recursion' > > > > -- > > Per olof Ljungmark > > +46 707 50 20 46 <tel:%2B46%20707%2050%2020%2046> > > Nethead AB > > Registered in Stockholm, Sweden > > SE556815226701 > > > > > > > > > > -- > > Michael Schuster > > http://recursiveramblings.wordpress.com/ > > recursion, n: see 'recursion' > > -- > Per olof Ljungmark > +46 707 50 20 46 > Nethead AB > Registered in Stockholm, Sweden > SE556815226701 > -- Michael Schuster http://recursiveramblings.wordpress.com/ recursion, n: see 'recursion'
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